Zhao Kuo, son of the Zhao general Zhao She, studied the art of war from his youth and believed that no one could match him. When he discussed war with his father, Zhao She could not refute him, but he would not call him good. “War is a place of death,” he told his wife, “and Kuo speaks of it lightly.” If Zhao ever made Kuo a general, he said, Kuo would destroy its army.
When the king gave Kuo the command against Qin, his mother wrote to the king that he must not lead. At Changping in 260 BC, Qin troops shot Kuo dead, and his surrendered army was buried alive. Sima Qian put Zhao’s total losses at 450,000. Because of her warning, the king spared his mother.
The idiom zhi shang tan bing, talking war on paper, comes from this story. Dictionaries define it as empty talk about theory that has nothing to do with reality.